1. Field of the Invention
The present invention relates to a storm shutter system for building openings, and more particularly, to such shutter systems of the accordion type that includes articulated shutter blade assemblies.
2. Description of the Related Art
Many designs for accordion storm shutter systems have been designed in the past that include articulated shutter blade assemblies to protect openings in buildings. These panel members are joined by hinge assemblies (and particularly including hinge pins) that receive and transmit most, if not all, the wind forces to the frame. These hinge assemblies are exposed to considerable shearing strain becoming the most vulnerable components of the systems.
Most of these systems are manufactured with extruded blade panels to reduce cost. This relatively inexpensive manufacturing process, however, injects some design limitations. Also, the blade panels require reinforcement to keep their thickness at a minimum with the consequent cost savings. These reinforcements are typically longitudinal folds since a completely flat panel is more susceptible to high winds for a constant thickness. Thus, the desirability of using in the prior art articulated hinge connections that permit the blade panels to open no more than 90 degrees for flat blade panels to form these folds. The present invention, however, introduces articulated non-flat blades with longitudinal fold reinforcements that open to 180 degrees. The folds are extruded with complementary shapes.
One of these systems is disclosed in U.S. Pat. No. 5,549,148 issued to Figueiredo, et al. in 1996 for a blade for accordion storm shutters. An articulated hinge connection is shown in FIGS. 10 and 11 of that patent. Figueiredo""s patented invention provides for hingedly mounted longitudinal blades forming an approximately 90-degree angle with respect to one another in one (closed shutter) configuration and substantially parallel to each other in the other (open shutter) configuration. The hinge assembly includes a socket and a knuckle with a journaled longitudinal pin. The socket includes two protruding internal ribs (inwardly) defining a shoulder that limits the movement of the knuckle to a 90 degrees angle. As shown in FIG. 2, the maximum angle that can be achieved by the longitudinal blades is approximately 90 degrees. The articulated assembly of the present invention, on the other hand, has two complementary fingers that act as stopper members and they are disposed outside the main socket making possible the movement to extend to an approximately 180 degree angle. This permits a user to use extruded blades that are formed with longitudinal bends or folds obviating the need to form these bends or folds with vulnerable hinge assemblies.
Applicant also believes that another related reference corresponds to U.S. Pat. No. 6,021,839 issued to Knezevich, et al. in 2000 for an accordion shutter system with improved header and sill configuration. Knezevich ""s patented invention provides support to the shutter blade while reducing load upon the guide pin. However, it differs from the present invention because Knezevich""s shutter system is a continuously extruded accordion blade with a male end and a female end that allows the shutter to interlock forming a hinge junction. The disposition of the blades in Knezevich""s shutter system limits the movement of the blades to a maximum angle of approximately 90 degrees. The articulated assembly of the present invention allows the disposition of the blades in a range having a minimum of approximately 4 degrees (in shutter open position) to 180 degrees (in shutter closed position).
Finally, Applicant believes that another related reference corresponds to U.S. Pat. No. 5,469,905 issued to McKinney, et al. in 1995 for a security and hurricane shutter. McKinney""s patented security and hurricane shutter is for horizontally disposed blades that are pivotally mounted in-between. However, it differs from the present invention because, although the distance between the inner and outer pivots can be varied, it is evident that the largest angle to be adjusted must keep the accordion-like structure shape (90 degrees) in order to keep the strength of the shutter system. The present invention not only has blades with longitudinal reinforcement folds for transmitting the bulk of the wind load to the frame, but all the pin members are kept inside (protected) the frame assembly for better structural stability under high winds load.
One of the common problems found in the prior art is that impact forces strain the hinge pins. Thus, regardless of the type of installation (horizontal or vertical structures) the hinge pin member is the weakest point of most of the accordion like shutter structures. Pins are typically exposed to considerable shearing strain making them the most vulnerable components of shutter system. In the present invention, the frame assembly is mounted outside the closures for building""s openings, such as doors or windows. The ends of the longitudinal folds of the blades rest against the longitudinal stoppers mounted on the frame assembly. Therefore, the force exerted by heavy winds or any other impact received by the panel members is transmitted to the ends of the flat portions of the longitudinal folds and then to the wall through the frame assembly thereby relieving the hinge assembly from most of the stress. The compression force transmitted through the hinge assembly is not as damaging as the shearing strain exposure in conventional shutter systems.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.
It is one of the main objects of the present invention to provide a storm shutter system that allows the disposition of reinforced longitudinal folds in articulated blade assemblies movable from a substantially parallel configuration to a fully expanded (180 degrees) configuration.
It is another object of this invention to provide a shutter system that reduces the stress applied to the hinge assemblies of the system by transmitting the load forces to the frame assembly (and wall) through a co-acting flat portion at the lateral ends of the longitudinal fold of the panel member.
It is yet another object of this invention to provide such a device that is inexpensive to manufacture and maintain while retaining its effectiveness.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.